Wednesday, April 30, 2025
Scientists work toward a vaccine for filoviruses, Ebola's deadly kin - phys.org
Vaccination and sampling schedule for RV456/EBL2003
Phase 2 Ad26/MVA Ebola vaccine trial. Credit: Science Translational Medicine (2025). DOI: 10.1126/scitranslmed.adq2496
Filoviruses
are among the globe's most lethal—indeed, so dangerous they can be handled only
in high-security laboratories. Yet, more than five decades after the discovery
of the Marburg virus and nearly 50 years after the first outbreak involving its
infamous cousin—the Ebola virus—questions still abound about the family
Filoviridae.
Members of this deadly family emerged through zoonotic
transmission, most likely jumping across multiple species barriers—from fruit
bats to simian species and forest antelopes, then eventually to humans. It's
theorized that humans may have contracted the viruses through hunting and
butchering bushmeat.
Mindful
that only two vaccines exist, and both were designed to prevent Ebola virus
infection, a multidisciplinary team of scientists at a U.S. military research
institute has analyzed whether one of those vaccines might also confer immunity
to other filoviruses. The research arrives as virologists at the University of
Texas Medical Branch in Galveston are testing the antiviral pill known as
obeldesivir, which so far appears capable of curing Rhesus macaques infected
with Ebola virus. The medication is the oral form of the intravenous drug
Remdesivir, originally developed for COVID-19.
Military
researchers, meanwhile, conducted an in-depth series of experiments to
determine whether a recombinant Ebola vaccine containing
components of multiple filoviruses could serve as an off-the-shelf choice to
prevent infection by filoviruses other than Ebola.
Their
findings, however, didn't produce the outcome they had hoped for. But the
discovery that unfolded has helped pave the way to a broader understanding of
what's needed for a multivalent vaccine that guards against multiple
filoviruses. Details of the research are reported in the journal Science Translational Medicine.
"Ebola
virus is a negative single-strand RNA virus from the family Filoviridae that
causes a virulent hemorrhagic fever, termed Ebola virus disease," writes
Dr. Thembi Mdluli, lead author of the new research and a computational
biologist at Walter Reed Army Institute of Research in Silver Spring, Maryland.
Just as
Ebolavirus is a negative single-strand RNA virus, so too are other filoviruses,
which also cause a devastating hemorrhagic fever. Filoviruses are known for
their morbidity and high mortality. Mduli and colleagues pointed to Marburg
outbreaks in Africa, where fatality rates have ranged between 83 and 88%.
"Marburg
virus—MARV—was discovered in 1967 and has caused mostly sporadic self-contained
outbreaks," Mdluli added, referring to the world's first filovirus
discovery. The isolation of the Marburg virus occurred after lab personnel in
Europe were infected by green monkeys from Uganda. Laboratory workers were
infected in Marburg and Frankfurt, Germany, as well as in Belgrade, Serbia. Of
the 31 people who were sickened, seven died.
In
addition to Ebola and Marburg viruses, other members of the filovirus family
include Sudan, Bundibugyo and Tai Forest viruses, all named after geographic
locations where they were first identified. The Ebola virus is named after the
Ebola River in the Democratic Republic of the Congo. Its first known appearance
was an explosive and deadly August 1976 outbreak. An estimated 280 people died.
The Walter
Reed researchers report that a vaccine to prevent infections caused by
filoviruses is critical. Likewise, virologists in Texas, working on the
obeldesivir antiviral research, say a single pill would solve a global health
problem.
"We're really trying to come up with something that is more practical, easier to use, that could be used to help prevent, control, and contain outbreaks," Thomas Geisbert, a virologist at the University of Texas Medical Branch, told Agence France Presse in March.
MVA, Ad26 and Ad26, MVA recipients showed strong
antibody (Ab) binding responses against EBOV GP antigens at peak immunity.
Credit: Science Translational Medicine (2025). DOI: 10.1126/scitranslmed.adq2496
Despite the
amount of time that filoviruses have circulated on Earth, they emerged only in
the 20th and 21st centuries. It has taken until recent years to develop
vaccines and monoclonal antibody therapies just for Ebola virus disease.
"Filoviruses are ancient relative to their
initial detection in humans. The most recent common ancestor of Filoviridae is
estimated to be several thousand years old," Mdluli asserted.
It was in the aftermath of the sweeping 2014 through
2016 West African Ebola outbreak that vaccine-development studies produced the
first Ebola inoculation, Ervebo, which was approved by the U.S. Food and Drug
Administration and the European Medicines Agency in 2019. It's manufactured by
Merck & Co. Vaccine candidates are in development for Marburg virus, but
there still isn't an approved immunization to prevent infection.
Mdluli and her colleagues chose to study the only
other approved Ebola vaccine, one developed by Belgium-based Janssen
Pharmaceuticals, a division of Johnson & Johnson. The Janssen Ebola vaccine
is a two-part regimen known as Zabdeno and Mvabea. The doses were designed to
be administered eight weeks apart.
The first part of the vaccine—the Zabdeno
dose—includes an adenovirus vector that ferries the vaccine's payload—the
genetic code for Ebola virus's sugary outer coating, its glycoprotein—into
human cells.
The second dose consists of a modified vaccinia Ankara
vector, the vehicle that carries the vaccine into cells. It encodes
glycoproteins from Ebola, Sudan and Marburg viruses, as well as the
nucleoprotein from the Tai Forest virus. In the study, the two vaccines were
administered to 583 people.
Volunteers hailed from multiple countries: Kenya,
Mozambique, Nigeria, Tanzania, Uganda, and the United States. Seventy-one
participants were from the U.S.
Volunteers were divided into two groups. This allowed
the team to vaccinate some participants in the manufacturer's prescribed order
for the two doses: Zabdeno first and Mvabea second.
With the second group, the team reversed the order of
the vaccines: Mvabea first, followed by Zabdeno, providing exposure to the
components of multiple filoviruses in participants' initial shots. Researchers
also studied 48 people who were infected during an outbreak of Bundibugyo
virus, a filovirus that emerged in Uganda in 2007.
When participants' blood was analyzed in the lab, it
revealed that antibodies were highly specific to fighting Ebola virus but
didn't react strongly to other filoviruses. The scientists also examined blood samples from the Bundibugyo survivors and discovered their antibodies
didn't put up much of a fight against other filoviruses, either.
Mdluli reported that her team's strategy provided only
limited protection against other members of the filovirus family.
"These results underscore the vaccine's potential to provide strong, species-specific protection against [Ebola virus] while highlighting the need for multivalent vaccines that can provide broader coverage for other filoviruses," Mdluli concluded.
by Delthia Ricks , Medical Xpress
Source: Scientists
work toward a vaccine for filoviruses, Ebola's deadly kin
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Tuesday, April 29, 2025
Saturday Citations: Huge eruptions from a black hole; the largest-ever functional brain map; origins of human musicality
Conversion occurring in a nanometric
system of two photons into an entangled state in their total angular momentum.
Credit: Shalom Buberman, Shultzo3d
A
study from Technion unveils a newly discovered form of quantum entanglement in
the total angular momentum of photons confined in nanoscale structures. This
discovery could play a key role in the future miniaturization of quantum
communication and computing components.
Quantum physics sometimes leads to very
unconventional predictions. This is what happened when Albert Einstein and his
colleagues, Boris Podolsky and Nathan Rosen (who later founded the Faculty of
Physics at Technion), found a scenario in which knowing the state of one
particle immediately affects the state of the other particle, no matter how
great the distance between them. Their historic 1935 paper was nicknamed EPR
after its three authors (Einstein–Podolsky–Rosen).
The idea that knowing the state of one
particle will affect another particle located at a huge distance from it,
without physical interaction and information transfer, seemed absurd to
Einstein, who called it "spooky action at a distance."
But groundbreaking work by another
Technion researcher, Research Prof. Asher Peres from the Faculty of Physics,
showed that this property can be used to transmit information in a hidden way—quantum teleportation, which is the basis for quantum communication. This
discovery was made by Prof. Peres with his colleagues Charles Bennett and
Gilles Brassard.
The phenomenon later received the
scientific name quantum entanglement, and for its measurement and implications, which
include the possibility of quantum computing and quantum communication, the
2022 Nobel Prize in Physics was awarded to Profs. Alain Aspect and Anton
Zeilinger, who previously received honorary doctorates from the Technion, and
their colleague Prof. John Clauser.
Quantum entanglement has been
demonstrated so far for a wide variety of particles and for their various
properties. For photons, particles of light, entanglement can exist for their
direction of travel, frequency (color), or the direction in which their electric
field points. It can also exist for properties that are harder to imagine, such
as angular momentum.
This property is divided into spin,
which is related to the photon's rotation of the electric field, and orbit,
which is related to the photon's rotational motion in space. This is
intuitively similar to Earth, which rotates on its axis and also orbits the sun
in a circular path.
It is easy for us to imagine these two
rotational properties as separate quantities, and indeed, photons bound in a
beam of light much wider than their wavelength. However, when we try to put
photons into structures smaller than the photonic wavelength—which is the
endeavor of the field of nanophotonics—we discover that it is impossible to
separate the different rotational properties, and the photon is characterized
by a single quantity, the total angular momentum.
So why would we even want to put photons
into such small structures? There are two main reasons for this. One is
obvious—it will help us to miniaturize devices that use light and thus squeeze
more operations into a small area cell, similar to the miniaturization of
electronic circuits.
The other reason is even more important:
this miniaturization increases the interaction between the photon and the
material through which the photon is traveling (or is near), thus allowing us
to produce phenomena and uses that are not possible with photons in their
"normal" dimensions.
In
a study published in
the journal Nature, the Technion
researchers, led by Ph.D. student Amit Kam and Dr. Shai Tsesses, discovered
that it is possible to entangle photons in nanoscale systems that are a thousandth the size of a hair, but
the entanglement is not carried out by the conventional properties of the
photon, such as spin or trajectory, but only by the total angular momentum.
The Technion researchers revealed the
process that photons undergo from the stage in which they are introduced into
the nanoscale system until they exit the measurement system, and A digital
representation of neurons in a section of a mouse's brain, part of a project to
create the largest map to date of brain wiring and function, in Seattle, Wash. Credit:
Forrest Collman/Allen Institute
This week, researchers
reported a brain circuit linked to the intensity of political
behavior.
Microbiologists found that the 2018 eruption of the Kīlauea volcano drove a rare, massive summertime phytoplankton bloom, the largest ever recorded in the North Pacific. And
a physics professor at the University of Alabama in Huntsville proposed a new model of the universe built on multiple singularities rather than a
single Big Bang.
Additionally, a huge, quasiperiodic
black hole flare is prompting a rethink about models of black hole behavior;
scientists have made the most detailed functional map of a brain to date; and anthropologists propose that the
transition to bipedal movement deeply influenced human
thinking, musicality
and communication:
Boring galaxy interesting, actually
In 2019, a boring galaxy that
nobody cared about 300 million light-years away started producing flashes of X-ray light in a clear bid for attention. Rolling their eyes
in a theatrical, passive-aggressive display, astronomers said, "FINE"
and aimed the Swift telescope at it but didn't find anything unusual.
But in February 2024, SDSS1335+0728
flared up again with bursts of X-ray emissions at regular intervals, an example
of seldom-observed quasiperiodic eruptions, in which a supermassive black hole wakes up from a long period of dormancy and has
a kind of tantrum, probably because a small astronomical object like a star,
planet or a smaller black hole is interacting with its rapidly spinning
accretion disk. The black hole at the center of this unremarkable galaxy is now
called Ansky.
Joheen Chakraborty, a Ph.D. student
at the Massachusetts Institute of Technology, said, "The bursts of X-rays
from Ansky are 10 times longer and 10 times more luminous than what we see from
a typical QPE." The astronomers say this indicates that current models of
quasiperiodic eruptions may need revisiting. Ansky's current series of
eruptions could represent a different phenomenon, such as gravity waves
interacting with the accretion disk.
Mouse takes red pill
Biologists at Baylor College of
Medicine have published the largest functional map of a brain ever made, comprising about 84,000 neurons in a region of a
mouse's visual cortex about the size of a poppy seed. Despite the tiny sample
area of the mouse brain, the researchers note that the map's stunning
complexity resembles a map of cosmological filaments.
The 3D reconstruction, colored to
delineate different brain connections, is the result of an experiment in which
the researchers showed a mouse snippets of video, including sports, animation
and scenes from "The Matrix." The mouse was engineered with a gene
that makes its neurons luminous when activated, and the researchers used a
laser-powered microscope to record the activation of individual cells in the
mouse's visual cortex as it watched the video images. Afterward, they shaved
that tiny piece of brain into 25,000 ultra-thin sections, taking 100 million
high-resolution images to reconstruct the neural connections in 3D.
Scientists at Princeton University
used AI to trace the filaments in the model and render the connections in
different colors so they could be individually identified. Ultimately, the goal
is to achieve a complete map of an entire mouse brain.
So I guess there's a long way to go
before I can nondestructively compile a complete functional model of my own
brain, which (judging from my physical brain) would do absolutely nothing but
remind me of embarrassing and humiliating things I did at parties and
repeatedly play the KARS-4-KIDS song.
Step theory
A multi-institutional team of
anthropologists theorizes that human musicality and
language may have arisen with bipedal movement. In fact, they suggest that the transition from
walking on four legs to two legs may have influenced creativity along with
changes to thinking and communication.
Dean Falk, professor of
anthropology at Florida State University, says, "Bipedal footsteps create
rhythmic and more predictable sounds of movement, in comparison with the way in
which our closest living relative, the chimpanzee, moves on all fours, with
irregular steps among rustling tree branches." Human walking pace is about
120 steps per minute, the same tempo as many
pieces of music.
They suggest that human baby talk arose as a substitute for physical contact with children—when humans began walking upright, small offspring could no longer cling to their parent's fur to maintain body contact. The special musicality of baby talk could have arisen to maintain contact between adults and children. "This may have stimulated the evolution of music and language," says co-author Matz Larsson.
by Chris Packham , Phys.org
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